Ventilation of dynamo-electric machines



"June 19, 1934. R. CLASON VENTILATION OF DYNAMO ELECTRIC MACHINES Original Filed Sept. 22. 1927 V 4 gwoento o fin my; C7010):

1 atknmur Patented June 19, 1934 I 1 g Q I VENTILATION F DYNAMO-ELECTBJC MACHINES Ragnar Clason, Flint, Mich., assignor to A 0 Spark Plug Company, Flint, Mich., a company of Michigan Application September 22, 1927. Serial No. 221,285 Renewed January 19, 1934 23 Claims. (Cl. 171-252) This invention relates to apparatus for cooling the plate 11 an integrally formed circular plate the working parts of dynamo-electric machines 15, whose outer edge is at substantially the same by circulating air over or around them. distance from the shaft 8 as the inner sides of The principal object of this invention is to the openings 12. On the outer surface of the provide in combination with a dynamo-electric plate 15 and perpendicular thereto are fixed 60 machine of the type in which the working parts blades 16 which extend from the hub 14 radially are enclosed within a casing, mechanism associbeyond the outer edge of the plate, beyond the ated with the rotor of the machine to remove openings 12, and overlap the portion 13 of the foreign matter from air so as to eliminate the plate 11 for a considerable distance. The blades possibility of the foreign matter being deposited 16 are quite narrow adjacent the hub, gradually 65 in and clogging the channels through which the increase in width up to the point A, whence, to air circulates over or around the working parts of the point y a of uniform W d from the machine and to circulate the cleaned air over point B, outwardly. g ad deflfease in Width or around the working parts of the machine. coming almost to a point at their outer ends.

. 15 Another object of the invention is to provide The element 1415--16 and the end of the 70 certain new and useful improvements in combined shaft 8 on which it is mounted are enclosed withair impellers and cleaners of the inertia type. in a housing 1'7, whose side walls rest and are For a better understanding of the nature and secured in a 'rabbet 18 in the end of the cylinobjects of the present invention, reference is made drical portion of the casing 6. The outer end of to the following description of the embodiments the housing is shaped to follow closely the con- 7 of my invention which are illustrated in the actour of the outer edges of the blades 16, as shown companying drawing. in Figure 1, except at the center where an open- In the accompanying drawing: ing 19 which is coaxial with the shaft 8 and cov- Flgure 1 is a view, mainly in side elevation, but ered by a screen 20 is provided. It will be noted partly in section on the line 11 of Figure 2, of that a V-shaped, circumferential groove 21, into an electric motor on which is installed air cleanwhich the tapered end portions of the blades 16 ing and ventilating apparatus in accordance with extend, is formed between the portion 13 of the my invention. plate 11 and the inclined portion of the end wall Figure 2 is a section on the line 22 of Figure 1. of the housing 17. In the wall of the housing 30 Figure'3 is a fragmentary, longitudinal section opposite the blades 16 and leading into the groove 5 through an electric motor on which is installed a 21, there are provided one or more dirt discharge modified form of air cleaning and ventilating apopenings 22. paratus. In its end adjacent the pulley 10, the casing 6 In the drawing, the reference character 5 indiis provided with openings 23 for the discharge of cates an electric motor whose working parts are air therefrom. It is preferable that the casing be enclosed within a casing 6 and supported by a airtight at all points other than the openings 12 base 7. The armature of the motor is carried by and 23 to insure that the cooling air forced into the shaft 8 which is journalled in bearings, such the casing by the element 141516 will travel as 9, at opposite ends of the casing and projects the full length of the casing and pass over all of 40 therethrough at both ends. To one projecting the parts within the casing before being disend of the shaft is fixed an ordinary pulley 10 charged therefrom. But even if there are leaks in any desired manner. in the casing, they will not serve as passages for Referring to the embodiment of my invention dirty air to enter it because the air in the casing shown in Figures 1 and 2, it will be seen that the is under pressure and air will escape from rather 45 plate 11, which closes the end of the casing disthan be drawn into the casing through the leaks. tant from the pulley l0 and carries one of the When the motor starts, the element 141516 bearings 9. is provided with sectoral air intake rotates and air is drawn thereby through the openings 12 at a distance from its center and screened opening 19 into the housing 17, the spaced form its circumference by the marginal screen 20 preventing the larger dirt particles from 50 portion of the plate designated as 13. Asshown entering with the air. After passing through the in the drawing, the plate 11 may be integral with opening 19, the air impinges against the plate 15 the cylindrical portion of the casing 6. To the and is caught by the blades 16 which give it a end portion of the shaft 8 which projects through rotary motion which throws it outwardly into the the plate 11, there is fixed so as to rotate therecircumferential groove 21 whence the dirt parwith a. hub 14 carrying on its inner end adjacent ticles, which are denser than the air, are discharged through the openings 22. The cleaned air passes over the portion 13 of the plate 11, through the openings 12 into the motor casing and travels through the casing, passing over and cooling the brushes, commutator, field coils and armature, and is discharged from the casing through the openings 23.

Referring to the modification shown in Figure 3, it will be seen that the plate 25 which closes the end of the casing 6, and which may be integral with the cylindrical portion thereof, differs from the plate 11 in having an annular central portion 26 which carries the bearing 9 extending outwardly of the casing beyond the plane of the outer portion of the plate 25. The plate 25 is provided with arcuate air intake openings 27 similar to the openings 12 shown in Figs. 1 and 2 and bounded on their inner sides by the portion 26 and on their outer sides by the marginal portion 28 of the plate. To the end portion of the shaft 8, which projects through the annular portion 26 of the plate 25, is fixed, so as to rotate therewith, a hub 29 carrying on its inner end adjacent the part 26 an integrally formed, circular plate 30 which extends radially beyond the outer sides of the openings 27. On the outer surface of the plate 30 and perpendicular thereto are fixed blades 31 which extend from the hub 29 radially outward beyond the circumference of the plate 30 and overlap the portion 28 of the plate 25 for a considerable distance. The blades 31 are quite narrow adjacent the hub 29, gradually increase in width up to the point C, whence, to substantially the circumference of the plate 30, they are of uniform width. Beyond the circumference of the plate, the outer edges of the blades are inclined rearwardly while the inner or rear edges are each provided with an integral rearwardly projecting extension 31a outward of the openings 27 and extending into close proximity to the portion 28 of the plate 25.

The blades 31 and the outer end of the shaft 8 are enclosed in a housing 33, whose side walls rest and are secured in a rabbet 34 in the end of the cylindrical portion of the casing 6. The outer end of the housing is shaped to follow closely the contour of the outer edges of the blades, as shown in the drawing, except at the center where an opening 35 coaxial with the shaft 8 and covered by a screen 36 is provided. As can be seen from the drawing, a channel-shaped, circum; ferential groove 37 into which the extremities and the portions 310. of the blades project, is formed between the inclined portion and the side wall of the housing and the portion 28 of the plate 25. In the wall of the housing and opposite the portions 31a of the blades, there are provided one or more dirt discharge openings 38.

In its end opposite the plate 25, the casing is provided with openings for the discharge of the air therefrom. It is preferable that the casing be airtight at all points other than these discharge openings and the intake openings 27 although this is not absolutely necessary for the reason given in connection with the description of the modification of my invention shown in Figures 1 and 2.

As the modification of my invention shown in Figure 3 operates similarly to that shown in Figms 1 and 2, a separate detailed description of its operation will not be necessary. It will be noted, however, that the fact that the plate 30 and the portion 28 of the plate 25 overlap will cause the air to take a sharper turn in passing into the openings 2'1 which will result in a better separation of the dirt from the air. The main portions of the blades 31 are spaced outwardly from the central portion of the plate 25 to provide a sufficiently large space 39 for the air to pass from the groove 37 to the openings 2'7.

Since the blades 16 and 31 are perpendicular to the axis of rotation of the shaft 8, my combined air cleaning and impelling apparatus will operate equally efficiently upon rotation of the armature shaft in either direction.

Although I have shown and described my combined air cleaning and ventilating apparatus as applied to an electric motor of the interiorly ventilated type, it is not limited to such a restricted use, but can also be used on electric motors of the exteriorly ventilated type and on electric generators, rotary converters and similar machines of either the interiorly or the exteriorly ventilated type. It can furthermore also be used in many other connections where simple, efficient air cleaning and ventilating apparatus is needed.

It is not necessary that the air discharge openings in the motor casing be positioned in the end opposite to that having the intake openings. It may be desirable in some instances to position them in the sides of the casing or in both the sides and the end.

I claim:

1. An electric machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, said end having openings therein spaced from its periphery and arranged about said shaft and spaced therefrom, means to clean air and circulate it through the casing including a bafile secured to the projecting end of the shaft and terminating adjacent the inner edges of the openings, blades secured to the shaft adjacent the baffle, and a housing secured to the casing and enclosing the bafile, the blades and the openings.

2. The invention claimed in claim 1 in which said blades extend beyond the periphery of the baffle.

3. The invention claimed in claim 1 in which said blades extend beyond the periphery of the bafile and overlap the portion of the end of the casing outward of the outer edges of said openings.

4. The invention claimed in claim 1 in which said housing has an opening therein substantially concentric with the shaft, and a second opening adjacent the outer ends of the blades.

5. In an electric machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, means to clean air and circulate it through the casing including a baffie secured to the projecting end of the shaft in close proximity to the end of the casing, blades secured to the surface of the bafiie distant from the end of the casing, and a housing secured to the casing and enclosing the blades and the battle.

6. In an electric machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, means to clean 1-10 air and circulate it through the casing including a battle secured to the projecting end of the shaft and spaced outwardly from the main portion of the end of the casing, blades on said baffle extending beyond the periphery of the baffle, and a housing secured to the casing and enclosing the blades and the baffle.

7. In an electric machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, means to clean air and circulate the cleaned air through the interior of the casing and over the working parts of the machine including, a baffle secured to the projecting end of the shaft, blades secured to the shaft and extending outwardly beyond the periphery of the plate, and a housing surrounding the blades and the baflle.

8. In an electric machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, means to clean air and circulate the cleaned air through the interior of the casing and over the working parts of the machine including, a baille secured to the projecting end of the shaft, blades secured to the shaft and extending outwardly beyond the periphery of the plate, a housing surrounding the blades and the baffle and having therein air inlet and dirt discharge openings, an opening in said casing communicating with the interior of the housing and the interior of the casing, and an opening in the casing distant from the last-mentioned opening.

9. The invention claimed in claim 8 in which the air inlet opening is coaxial with the shaft, the dirt discharge opening is located adjacent the ends of the blades, and the openings in the easing are located at opposite ends thereof.

10. In an electric machine, a rotor, a stator,

a shaft on which the rotor is mounted, a housing which surrounds the rotor and the stator, a closure for one end of the housing through which the shaft projects and in which there is provided an opening, and means to effect an inertia separation of foreign matter from airand to circulate the cleaned air through the interior of the housing so asto cool the working parts of the machine, including fan blades secured to the projecting end of the shaft, a baflie located between the fan blades and the closure and terminating outwardly of the inner edge of the opening and inwardly of the outer ends of the fan blades, and an air directing hood associated with the fan blades.

11. In an electric machine, a rotor, a stator, a shaft on which the rotor is mounted, a housing which surrounds the rotor and the stator, a closure for one end of the housing through which the shaft projects and in which there is provided an opening which is spaced inwardly from the boundary of the closure, and means to effect an inertia separation of foreign matter from air and to circulate the cleaned air through the interior 'of the housing so as to cool the working parts of the machine including fan blades secured to the projecting end of the shaft and extending outwardly beyond the opening, a baflle located between the fan blades and the closure and terminating outwardly of the inner edge of the opening and inwardly of the outer ends of the fan blades, an air directing hood which is associated with the fan blades and in which there is provided an air intake opening which is substantially co-axial with the shaft and whose outer edge portions are located adjacent the outer edge portions of the closure, and a dirt discharge opening adjacent the juxtaposed edges of the hood and the closure.

12. The invention claimed in claim 10 in which the baffle is fixed to the fan blades so as to rotate' therewith.

13. The invention claimed in claim 10 in which the baflle is spaced outwardly from the closure and the fan blades are provided with extensions on their outer ends which are located on the side of the baffle adjacent the closure.

14. In an electric machine, a rotor, a stator, a shaft on which the rotor is mounted, a'housing which surrounds the rotor and the stator, a closure for one end of the housing through which the shaft extends and in which there is provided an opening which is located inwardly of the boundary of the closure, and means to effect an inertia separation of foreign matter from air and to circulate the cleaned air through the interior of the housing so as to cool the working parts of the machine, including fan blades secured to the projecting end of the shaft and having portions projecting outwardly beyond the opening, a bafile located between the fan blades and the closure spaced outwardly from the latter and terminating outwardly of the inner edge of the opening and inwardly of the outer ends of the fan blades, extensions on the outer-ends of the fan blades located on the side of the baffle adjacent the closure, an air directing hood which is associated with the fan blades and in which there is provided an air intake opening substantially coaxial with the shaft and whose outer edge portions are located adjacent the outer edge portions of the closure, and a dirt discharge opening adjacent the juxtaposed edges of the hood and the closure.

15. The invention claimed in claim 14 in which the baflle is secured to the fan blades so as to rotate therewith.

16. In an electric machine, a rotor a stator, a shaft on which the rotor is mounted, a housing which surrounds the rotor and the stator, a

closure for one end of the housing through which the shaft projects and in which there is provided an opening, and means to effect an inertia separation of foreign matter from air and to circulate the cleaned air through the interior of the housing so as to cool the working parts of the machine including, fan blades secured to the projecting end of the shaft, a baflle located between the fan blades and the closure and terminating,

inwardly of the outer ends of the fan blades, an air directing hood associated with the fan blades, an air intake opening in the hood, and dirt discharge opening adjacent the ends' of the fan blades.

1'7. The invention claimed in claim 16 in which the baffle is spaced outwardly from the closure and the fan blades are provided with extensions on their outer ends which are located on the side of the baffle adjacent the closure.

18. An electric machine which includes a casing and a rotatable shaft'which projects through one end of the casing, openings in the mentioned end of the casing between its circumference and the shaft, means to clean air. and circulate it through the casing including a baflle secured to the projecting end of the shaft at a distance from the main portion of the end of the casing and extending radially beyond the openings therein, blades which are secured to the outer surface'of and extend radially beyond the circumference of the baffle, and a housing which is secured to the casing and encloses the baflle, the blades and the openings. v

19. An electric machine which includes a casing and a rotatable shaft which projects through one end of the casing, an annular portion on the mentioned end of the casing which surrounds the shaft and extends outwardly beyond the main portion of the end of the casing, openings in the mentioned end of the casing between its circumference and the annular portion, means to clean air and circulate it through the casing, including a bafiie which is secured to the projecting end of the shaft and extends radially beyond the'openings, blades which are located on the outer surface of and extend radially beyond the circumference of the baiiie, and a housing secured to the casing and enclosing the baffle, the blades and the openings.

20. The invention claimed in claim 19 in which there are provided on the outer ends of the blades portions which extend toward and into close proximity to the main portion of the end of the casing.

21. An electric machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, said end having openings therein spaced from its periphery and arranged about said shaft and spaced therefrom, means to clean air and circulate it through the casing including a baiile secured to the projecting end of the shaft and spaced outwardly from the main portion of the end of the casing and extending radially beyond said openings, blades secured to the shaft outwardly of the baiiie, and a housing secured to the casing and enclosing the battle, the blades and the openings.

22. An electric machine having a casing and a rotatable shaft within thecasing and projecting through one end thereof, said end having an an nular portion surrounding the shaft and extending outwardly beyond the main portion of the end of the casing, said end also having an opening therein outwardly of the annular portion and spaced from the periphery of the end of the casing, means to clean air and circulate it through the casing including a bame secured to the projecting end of the shaft and extending radially beyond the opening, blades on the outer surface of the baiiie, and a housing secured to the casing and enclosing the baiiie, the blades and the openings.

23. An electrical machine having a casing and a rotatable shaft within the casing and projecting through one end thereof, means to clean air and circulate the cleaned air through the interior of the casing and over the working parts of the machine including, fan blades secured to the projecting end of the shaft, openings in the casing adjacent the periphery thereof, a housing enclosing the fan blades and the openings and having therein an air inlet opening on the side of the fan blades distant from the flrstmentioned openings and a dirt discharge opening adjacent the ends of the fan blades.

RAGNAR CLASON. 

